Apparatus and method for controlling electromagnetically operable engine valve assembly

Description

[0001] The present invention relates to an electromagnetically operable engine valve assembly for an internal combustion engine according to the preamble part of the independent claims 1 and 17, and to a method applicable to the electromagnetically operable engine valve assembly according to the preamble part of the independent claim 18.

[0002] From WO-A-99/13202 an electromagnetically operable engine valve assembly and a method applicable thereto as indicated above are known.

[0003] Recently, an adoption of the, so-called, electromagnetically operable engine valves as intake and exhaust valves of an internal combustion engine with an electromagnetic actuator as a power device has been discussed.

[0004] In this kind of engine valve, such an initialization control that a movable element rested on a neutral position is moved to an initial position (namely, a position corresponding to a valve closure state) is carried out during an engine start.

[0005] To achieve the initialization control, such a technique as to utilize a pendulum motion of a spring-mass oscillation system constituting the spring and movable element and to alternatingly supply a power to a pair of electromagnets disposed on upper and lower parts of the movable element at a timing which is coincident with a specific oscillation frequency of the movable element.

[0006] According to the above-described technique, the resonance in the oscillation system is induced, the movable element rested is gradually oscillated widely (an amplitude of the oscillation is gradually increased) so that the movable element can be moved to the initial position.

[0007] JP-9-195736 published on July 29, 1997 and JP-10-288014 published on October 27, 1998 exemplify the initialization control described above.

[0008] However, in such a case where the engine is started under the low temperature region (especially, under an extremely low temperature region between - 30°C and -20°C, aviscosityof the engine lubricatingoil in amovable section (including the movable element and its surrounding portion) is increased. To perform the initialization utilizing such a pendulum motion as described in the BACKGROUND OF THE INVENTION (hereinafter, referred to as a resonance initialization), a current value for the one of the electromagnets required to develop the resonance initialization becomes remarkably increased.

[0009] As described above, the resonance initialization is not only disadvantageous under the engine low temperature region but also may cause the movable element to be landed onto the one of the pair of electromagnets which is energized to attract the movable element at a high velocity since an electro-magnetic force acted upon the movable section becomes excessive when a large current is, at the first time, supplied to the attracted side electromagnet if the resonance initialization is tried to be executed even under the low temperature region. Such a violent collision of the movable element against the corresponding electromagnet is a problem to be avoided from the standpoint of vibration, noise, and durability of the movable element and valve body.

[0010] To solve such a problem as described above, a software control technique utilizing a detected position information of the movable element to reduce a landing velocity has been proposed.

[0011] According to the proposed software control technique, a highly accurate control of the landing velocity can be achieved by using a model constant (for example, mass, friction, and spring constant) related to the electromagnetically operable engine valve which is a controlled system. Thus, the collision of the movable element against each of the electromagnets can be suppressed.

[0012] However, it is difficult to always perform a stable control even if such a software control technique as described above is applied to the electromagnetically operable engine valve. This is because a friction (representing a magnitude of a friction force based on a viscosity of the lubricating oil of the movable section) which is the object of the above-described model constant is largely varied in accordance with a temperature variation and its value is uncertain under the low temperature region.

[0013] It is, therefore, an objective of the present invention to improve an electromagnetically operable engine valve assembly and a method applicable thereto as indicated above so as to be capable of executing the initialization control which can stably suppress the collision of the movable element against each or one of the pair of electromagnets and can reduce the power consumption as low as possible under the low temperature region which would make it difficult to execute a favorable resonance initialization due to the increase in the viscosity resistance.

[0014] The objective is solved according to one aspect of the present invention by an electromagnetically operable engine valve assembly for an internal combustion engine, comprising a movable element; a spring element to bias the movable element at a neutral position; an electromagnet unit faced against the movable element; a control apparatus to control a current supplied to the electromagnet unit to drive the movable element so as to regulate a displacement of a valve body associated with the movable element, the control apparatus comprising an initialization control section and a position detector enabled to detect a position of the movable element with respect to the electromagnet unit, wherein the initialization control section executes an initialization control such that the current is continuously supplied to the electromagnet unit to move the movable element rested at the neutral position to an initial position, and wherein means are provided for a repetition of the execution of continuous current supply controls with interruption of the continuous current supply between each of them, only the last one of which being suitable for bringing the moveable element in the initial position, wherein the control apparatus further comprises a first current supply control section that performs a feedback control of the current supplied to the electromagnet unit during the execution of the initialization control by a feedback control gain on the basis of the position of the movable element detected by the position detector; and a feedback control gain varying section that varies the feedback control gain in such a manner that as the movable element becomes nearer to the initial position, a velocity of the movable element to arrive at the initial position becomes reduced when the initialization control section executes the initialization control repeatedly until the initialization control has succeeded in moving the movable element to the initial position during an engine start.

[0015] The objective is further solved according to another aspect of the present invention by an electromagnetically operable engine valve assembly for an internal combustion engine comprising a movable element; a pair of springs to bias the movable element at a neutral position; a pair of electromagnets, each electromagnet being faced against the movable element; a control apparatus to control a current supplied to one of the pair of electromagnets to drive the movable element so as to regulate a displacement of a valve body associated with the movable element, the control apparatus comprising an initialization control section and a position detector enabled to detect a position of the movable element with respect to one of the pair of electromagnets; wherein the initialization control section executes an initialization control such that the current is continuously supplied to one of the pair of electromagnets to move the movable element rested at the neutral position to an initial position; and wherein means are provided for a repetition of the execution of continuous current supply controls with interruption of the continuous current supply between each of them, only the last one of which being suitable for bringing the moveable element in the initial position, wherein the controller further comprises a first current supply control section that performs a feedback control of the current supplied to one of the pair of electromagnets during the execution of the initialization control by a feedback control gain on the basis of the position of the movable element detected by the position detector; and a feedback control gain switching section that switches the feedback control gain in such a manner that as the movable element becomes nearer to the initial position, a velocity of the movable element to arrive at the initial position becomes reduced when the initialization control section executes the initialization control repeatedly until the initialization control has succeeded in moving the movable element to the initial position during an engine start.

[0016] The objective is further solved according to still another aspect of the present invention by a method applicable to an electromagnetically operable engine valve assembly in an internal combustion engine, the electromagnetically operable engine valve assembly comprising a movable element; a spring element to bias the movable element at a neutral position; an electromagnet unit faced against the movable element; and a control apparatus to control a current supplied to the electromagnet unit to drive the movable element so as to regulate a displacement of a valve body associated with the movable element, and the method comprising executing an initialization control such that the current is continuously supplied to the electromagnet unit to move the movable element rested at the neutral position to an initial position; repeating the execution of continuous current supply controls with interruption of the continuous current supply between each of them; bringing the moveable element in the initial position by only the last one of the continuous current supply controls; and detecting a position of the movable element with respect to the electromagnet unit, wherein there are provided performing a feedback control of the current supplied to the electromagnet unit during the execution of the initialization control by a feedback control gain on the basis of the detected position of the movable element; varying the feedback control gain in such a manner that as the movable element becomes nearer to the initial position, a velocity of the movable element to arrive at the initial position becomes reduced when executing the initialization control repeatedly until the initialization control has succeeded in moving the movable element to the initial position during an engine start.

[0017] Further preferred embodiments of the present invention are laiddown in the further subclaims. In the following, the present invention is explained in greater detail by means of several embodiments thereof in conjunction with the accompanying drawings, wherein:

[0018] Fig. 1A is a schematic circuit block diagram of a control apparatus for an electromagnetically operable engine valve in a preferred embodiment according to the present invention.

[0019] Fig. 1B is a schematic block diagram of acontroller shown in Fig. 1A.

[0020] Fig. 2 is an operational flowchart representing a current supply control routine at a time of engine start executed in the control apparatus shown in Fig. 1A.

[0021] Fig. 3 is a schematic control block diagram of the control apparatus shown in Fig. 1A.

[0022] Fig. 4 is an operational flowchart representing an example of an initialization routine at a time of engine low temperature executed in the control apparatus.

[0023] Fig. 5 is a diagram representing trajectories of a movable element as a result of execution of an example of the initialization routine at the time of engine low temperature shown in Fig. 4.

[0024] Fig. 6 is a diagram representing trajectories of the movable element as a result of execution of another example of the initialization routine at the time of engine low temperature than that shown in Fig. 4.

[0025] Fig. 7 is a diagram representing trajectories of the movable element as a result of execution of the initialization routine at the time of engine low temperature in the case of a still another example of the initialization routine than that shown in Fig. 4.

[0026] Fig. 8 is a diagram representing trajectories of the movable element as a result of execution of the initialization routine at the time of engine low temperature in the case of a further another example of the initialization routine than that shown in Fig. 4.

[0027] Fig. 9 is an operational flowchart of a current supply control routine at a time of normal engine drive executed by the control apparatus for the electromagnetically operable engine valve in the preferred embodiment shown in Fig. 1A.

[0028] Fig. 10 is an operational flowchart representing one example of a landing control routine at the time of a normal (ordinary) engine drive.

[0029] Reference will hereinafter be made to the drawings in order to facilitate a better understanding of the present invention.

[0030] Fig. 1A is a schematic circuit block diagram of a control apparatus for an electromagnetically operable engine valve in a preferred embodiment according to the present invention. The control apparatus for the electromagnetically operable engine valve in the preferred embodiment shown in Fig. 1A is applicable to intake valve and/or exhaust valve of an internal combustion engine.

[0031] A port 2 communicated with an intake air passage or exhaust passage of the engine is formed on a cylinder head 1 attached on an upper part of a cylinder block. It is noted that in Fig. 1A, only a single port is shown.

[0032] A valve body 3 of the electromagnetically operable engine valve as a controlled system is disposed in port 2 to constitute the intake valve or exhaust valve of the engine.

[0033] Valve body 3 is slidably held within cylinder head 1 and guided vertically within cylinder head 1. A retainer 4 is fixed on an upper end of an axle portion of valve body 3. A spring 5 is intervened between a housing wall portion 100 faced against retainer 4 and a valve open direction of port 2 to bias valve body 3 to a valve closure direction.

[0034] In addition, a lower end of a guide axle member 7 to which a plate-like member 6 (hereinafter, referred to as a movable element) made of a soft magnetic property material is integrally attached is brought in contact with an upper end of the axle part of valve body 3. Another retainer 8 is fixed on an upper part of the guide axle member 7. Another spring 9 extended between the housing wall portion 100 faced against the port 2 and retainer 8. Consequently, movable element 6 is biased at a valve open direction and, therefore, valve body 3 is biased toward the valve open direction.

[0035] Both of valve body 3 and movable element 6 are integrally movable and movable element 6 , in the integrated state with the valve body 3, is biased toward a neutral position. The neutral position is defined as an intermediate position between valve full open and full closure positions. It is noted that the axle portion of valve body 3 and guide axle member 7 are not limited to be separate from each other but may be continuing member.

[0036] In addition, both valve opening and valve closure electromagnets 10 and 11 are disposed in valve housing 100 against movable element 6 with a predetermined interval of space. Guide axle member 7 is supportably inserted into a guide hole penetrated through valve open and closure electromagnets 10 and 11 so as to be enabled to make a smooth movement along the guide hole. Then, it is preferable that the neutral position of the movable element is set at an approximately center position between valve open electromagnet 10 and valve closure electromagnet 11.

[0037] Furthermore, a position sensor 31 to measure a position of movable element 6 is disposed and the position information from the position sensor 31 is outputted to a controller 21. The position sensor 31 is constituted by a laser displacement meter in the preferred embodiment and can be disposed within housing 100. AHall effect device or eddy current sensor may be used as the position sensor. In these alternative cases, such a device as described above may be disposed on upper end of guide axle member 7 to indirectly measure the position of movable element 6 via the guide axle member 7.

[0038] The controller 21 has functions as control gain switching section, a first current supply control section, and a second current supply control section. Controller 21 outputs a power supply command to a drive circuitry 23 for one of valve open and valve closure electromagnets 10 and 11 which is the object to be driven during an engine start and outputs the power supply command to the drive circuit on the basis of a valve open or valve closure command issued from an engine controller 22 during a normal engine drive. The drive circuitry 23 supplies a current to one of valve open and closure electromagnets 10 and 11 which is to be driven from a power supply (not shown) in response to the power supply command.

[0039] A temperature sensor 32 outputs a temperature indicative signal to controller 21. Temperature sensor 32 can detect a temperature of an engine lubricating oil or that corresponding to the lubricating oil. In the preferred embodiment, the temperature sensor 32 detects an engine coolant temperature Tw as the temperature corresponding to the engine lubricating oil. Controller 21 furthermore receives a power supply current i to each of valve open and closure electromagnets 10 and 11 from drive circuitry 23.

[0040] As shown in Fig. 1B, controller 21 includes a microcomputer generally having a CPU 21a (Central Processing Unit), a ROM 21b (Read Only Memory), a RAM 21c (Read Only Memory), Input Port 21d, an Output Port 21e, a common bus.

[0041] Next, control contents executed by controller 21 will be described below.

[0042] As described above, movable element 6 is biased at a neutral position by means of the pair of upper and lower springs 5 and 9 and sizes and spring constants of these springs 5 and 9 are designed so that movable element 6 is rested on an approximately center of these electromagnets with a power supply turned off state to both of valve open and closure electromagnets 10 and 11.

[0043] During the engine start, an engine start purpose current supply control is carried out for a predetermined electromagnet (either of valve open or valve closure electromagnet 10 or 11) to be driven so that the movable element 6 rested on a neutral position is driven to move. Then, movable element 6 is positioned at a predetermined initial position (in the preferred embodiment, a landed position of the valve closure electromagnet 11) to initialize the position of movable element 6. At this time, movable element 6 is initialized and its state is maintained until the engine start is completed.

[0044] Fig. 2 shows an operational flowchart representing the control contents by controller 21 at the time of engine start. According to the current supply control based on the flowchart, the above-described initialization can be achieved. Hereinafter, the operational flowchart shown in Fig. 2 will be described below.

[0045] At a step S1 (step is, hereinafter, abbreviated simply as S, controller 21 reads the coolant temperature Tw.

[0046] At S2, controller 21 determines whether the read temperature Tw is equal to or below a predetermined value To to select the control contents of the initialization.

[0047] If the controller 21 determines that the read temperature Tw is equal to or below a predetermined value To (Tw ≦ To), the routine goes to S3 to select the low temperature initialization. If No (Tw > To) at S2, the routine goes to a S4 at which the resonance initialization is carried out. The predetermined value To is a value representing a boundary between an ordinary temperature region and a low temperature region and, for example,-10 °C although the value is dependent on a kind (quality) of the used lubricating oil.

[0048] [0048] If controller 21 selects the resonance initialization at S4, each of valve open and closure electromagnets 10 and 11 receives alternatingly the current supply at a period corresponding to a specific oscillation frequency of a spring mass oscillation system constituted by a movable section including the springs 5 and 9, valve body 3, and guide axle member 7. Therefore, the resonance of this oscillation system is induced, an amplitude of movable element 6 is gradually increased, and the movable element 6 can soon be reached to the initial position.

[0049] On the other hand, controller 21 selects the low temperature purpose initialization at S3. In this case, the alternative current supplying method is not carried out but a continuous current supply to valve closure electromagnet 11 is carried out. As described above, at a low temperature region, the friction becomes large so that a considerable electro-magnetic force is required to drive movable element 6 rested. Then, if after movable element 6 started to be moved and a constant quantity of current is supplied, movable element 6 is gradually accelerated and may violently collide against valve closure electromagnet 11.

[0050] As described above, at a low temperature region, the friction becomes large so that a considerable electro-magnetic force is required to drive movable element 6 rested. Then, if, after movable element 6 starts to be moved and a constant quantity of current is supplied, movable element 6 is gradually accelerated and may violently collide against valve closure electromagnet.

[0051] To avoid such a phenomenon, during the initialization at the time of engine low temperature, a deceleration of movable element 6 before the landing is achieved. The current supplied to valve closing electromagnet 11 is feedback controlled as a control gain G1 on the basis of position information from position sensor 31 (refer to Fig. 3).

[0052] However, under the low temperature region, the magnitude of friction is not certain. Since it is difficult to set the control gain G1 which is always most appropriate. Hence, a dynamic setting of the feedback control gain G1 is carried out to avoid excessive setting. Hereinafter, the control contents of low temperature initialization will be described in details with reference to the flowchart of Fig. 5.

[0053] At S11, controller 21 sets the control gain G1 (feedback control gain). The control gain G1 is, at the first time, set to an initial value G1₁ which is relatively small. The current supply current flowing through valve closure electromagnet 11 is feedback controlled through the control gain G1₁ on the basis of the contents of the subsequent steps.

[0054] If the set control gain G1₁ is too small to develop a sufficient electro-magnetic force so that movable element 6 remains rested or does not reach to the initial position although the movement is started, the routine returns to S11 to again set the control gain G1.

[0055] The setting of control gain G1 can be carried out in accordance with a rule described in the following equation: G1_n = G1_n-1 + ΔG --- (1), wherein G1_n-1 denotes a control gain previously set at this step and ΔG denotes a predetermined gain increment. S11 corresponds to gain switching section. It is noted that the initial value G1₁ may be set to zero.

[0056] At S12, controller 21 read a position z of movable element 6. At S13, controller 21 calculates a target position z_t of movable element 6. The target position z_t can arbitrarily be set as a function based on an elapse time t after the start of current supply. For example, a variation rate of target position z_t is gradually reduced from an appropriate timing after the power supply start. Consequently, the deceleration of movable element is achieved to suppress the collision of movable element 6 against valve closure electromagnet 11.

[0057] At S14, controller 21 adds a feedback correction current formed by a multiplication of the control gain G1 with a deviation of (z_t - z) between target position z_t of movable element 6 and actual position z to an actual current I to device a target current i* to be supplied to valve closure electromagnet 11.

[0058] At S15, controller 21 controls drive circuitry 23 to supply target current i* to the corresponding electromagnet 10 or 11. Consequently, a counter electromotive force is generated on the corresponding electromagnet 10 or 11 along with a movement of movable electrode 6 to determine a current to be actually supplied to this electromagnet. An attracting force f of the corresponding electromagnet is acted upon movable element 6 in accordance with the actual current and position z of movable element 6 and movable element 6 is driven toward initial position against the spring force of the springs 5 and 9.

[0059] S 12 through S15 correspond to first current supply control section. At S16, controller 21 determines if a reverse return of movable element 6 to the neutral position is detected. This step serves to detect a state in which since the control gain G1 set at S11 is so small that a sufficient electromagnetic force to follow the target position z_t and elasticity of both springs 5 and 9 causes movable element 6 to return to the neutral position direction. Hence, for example, with velocity v of movable element 6 derived and the reverse turn is detected when the velocity v indicates a negative value with respect to the forwarding direction. Such a reverse turn detection of movable element 6 as described above can detect a failure in the initialization control. Hence, S16 can constitute determining section to determine if the initialization has succeeded.

[0060] In a case where the reverse turn of movable element 6 is detected (Yes) at S16, the routine goes to S17. At S17, controller 21 turns off the power supply to valve closure electromagnet 11. Then, the routine goes to S11. That is to say, the oscillation of movable element 6 is stopped and is rested, and, thereafter, control gain G1 is switched in accordance with the above equation (1), and the initialization control process of S12 through S15 is again executed.

[0061] On the other hand, if the reverse turn of movable element 6 is not detected (No) at S16, the routine goes to S18. At S18, controller 21 determines whether movable element 6 has reached to the initial position and the landing is completed. If movable element 6 is in a midway through stroke, the routine returns to S12 to continue the initialization control process using the same control gain G1. If the landing is completed (Yes) at S18, the present routine shown in Fig. 4 is returned and its state is maintained until the engine start is completed.

[0062] Fig. 5 shows trajectories of movable element 6 when the above described current supply control routine during the engine low temperature is executed. The control gain G1 is, in accordance with the above equation (1), augmented by a constant quantity for each execution of the initialization control from the initial value G1₁ which is relatively small value. As a result of this, a peak point P1_n (substantially equal to the reverse turn point described above) of the displacement of movable member 6 approaches gradually to the initial position from the peak point P11 in the case where the control gain G11 is executed at the first time as the number of times the initialization is executed are increased. By a sixth number of times the initialization is carried out, movable element 6 is landed onto the corresponding electromagnet upon an elapse of a time t1₆ from a time at which the start of power supply is executed so that the initialization has been achieved.

[0063] In the embodiment, according to the setting rule described in the above equation (1), the initialization upon the start of engine can be achieved for an appropriate time duration. However, the present invention is not limited to this but the control gain G1 may be set at a different variation rate for each execution of the initialization control. For example, in the setting rule described in the following equation (2), the control gain G1 can be set in accordance with an un-arrival distance d_n-1 to the initial position of movable element 6 which is caused by the previously executed initialization control. In the equation (2), α denotes a constant.
That is to say,

[0064] Fig. 6 shows the trajectory of movable element 6 in accordance with the above equation (2). Movable element 6 returned with the un-arrival distance d₁ left by means of the initialization control at the control gain G1₁ which is relatively small arrives at the close proximity to the initial position in accordance with the control gain G1₂ set in accordance with the above described rule described in the equation (2) (for convenient purpose, the trajectories by the second through fifth number of times the execution of initialization is carried out are not shown in Fig. 6). According to the sixth number of executions, movable element 6 is landed after the elapse of time t2₆ from the time at which the power supply is started.

[0065] The control gain G1 may be switched to the value based on the number of times the initialization controls have been executed. For example, the control gain G1 may be a value which accords with the magnitude of a square root based on the number of executions n (namely, f(n)). For example, as shown in the following equation (3), a square root of the execution number of times n is taken as f(n) = n by which a constant β is multiplied so that the control gain G1 may approximately be set.
That is to say,

[0066] Fig. 7 shows the trajectories of movable element 6 in a case where m = 2 (namely, G1_n = β x n^1/2) in accordance with the following equation (3).

[0067] As compared with the case in accordance with equation (1) (refer to Fig. 5), control gain G1 is set to a relatively large value at an earlier stage and is converged into a constant maximum value whenever the number of times the executions n have been increased. Hence, movable element 6 can reach to the proximity to the initial position from the first time execution (peak point P3₁) and, from the peak point P3₁, movable element 6 can gradually be converged into the initial position. Hence, Fig. 7 indicates that the initialization has been completed according to the sixth-number execution. However, if a constant β and function f(n) are approximated, it is possible to achieve the initialization at a less number of executions. If the number of times the executions of initializations are set to be constant, amore smooth landing of movable element 6 can finally be achieved.

[0068] Furthermore, control gain G1 may be a value which accords with a magnitude of a logarithm on a value (namely, g(n)) based on the number of times executions of initializations are carried out. For example, as described in the following equation (4), g (n) = n + 1, a logarithm of a value to which 1 is added is taken, and a constant ε is multiplied by the logarithm. That is to say,

[0069] Fig. 8 shows trajectories of movable element 6 in the case where the control gain G1 is in accordance with equation (4), a base a is set to e (e = 1 + 1/1! + 1/2! + 1/3! + --- = 2.71828---), and G1_n ε x ln(n + 1). In the same case (refer to Fig. 7) as the above equation (3), control gain G1 is set to a relatively large value at an earlier stage. Whenever the number of times the executions of initializations n are increased, the control gain G1 is converged into the constant maximum value. Consequently, to make constant and function g(n) more appropriate, the number of times the executions of initializations are carried out can be reduced and the smooth landing of movable element 6 can be achieved.

[0070] As described above, the initialization can be completed and, when the engine start is completed, the engine is transferred to the normal engine drive.

[0071] Fig. 9 shows an operational flowchart representing the control contents by controller 21 during the normal engine drive. The power supply control based on the flowchart of Fig. 9 drives the intake valve or the exhaust valve so that a gas exchange can favorably be achieved. The detailed explanation of the flowchart shown in Fig. 9 will be hereinafter made.

[0072] At S21, controller 21 reads valve open or valve closure command on the intake or exhaust valve from the engine controller 22.

[0073] At S22, controller 21 determines whether the read command indicates the valve open command. If Yes (valve open command) at S22, the routine of Fig. 9 goes to S23. If No (not valve open command) at S22, the routine jumps to S25.

[0074] At S23, controller 21 turns off the power supply to valve closure electromagnet 11. Although movable element 6 displaces in the lower direction as viewed from Fig. 1A due to the elasticity of both springs 5 and 9, an energy loss is developed due to an effect of the friction on the oscillation system during the stroke of movable element. Therefore, at S24, controller 21 supplies the power to valve open electromagnet 10 in a midway through the stroke so as to assist energizing a motion of movable element 6 by means of electro-magnetic force. If the supplied current is maintained constant, movable element 6 is accelerated as movable element approaches to the attracted side electromagnet and these elements of movable element 6 and the attracted side electromagnet may collide against each other. Hence, the deceleration of movable element 6 is carried out before movable element 6 lands onto the attracted side electromagnet. To achieve this object, the feedback control utilizing the positional information related to movable element 6 can be applied.

[0075] Fig. 10 shows a detailed operational flowchart at S24 shown in Fig. 9.

[0076] That is to say, at S31, controller 21 reads the coolant temperature Tw.

[0077] At S32, controller 21 determines whether the read coolant temperature Tw is equal to or below a predetermined value T1 (for example, - 10°C), namely, whether the engine is presently within a low temperature region. It is noted that although, in the embodiment, the predetermined value T1 is set to be equal to the predetermined value To described above, the present invention is not limited to this condition but the predetermined value T1 may be set to another more appropriate value. If the engine falls in the low temperature region (namely, Tw ≦ T1), the routine goes to S33. At S33, controller 21 sets control gain G2 to G1 by which the initialization control has succeeded (G1₆ in the case of Fig. 6). On the other hand, if the engine does not fall in the low temperature region (No) at S32, the routine jumps to S34 at which control gain G2 is set to a value prepared for an ordinary temperature application.

[0078] Since the contents of S35 through S38 may be the same as those of S12 through S15.

[0079] Referring back to Fig. 9, if the command from engine controller 22 is determined not the valve open command (No), the routine goes to S25. At S25, controller 21 determines whether the read command is the valve closure command. If controller 21 determines that the read command is the valve closure command, the routine goes to SS26. If No at S25, the present routine shown in Fig. 9 is returned. At S26, controller 21 turns off the power supply to valve open electromagnet 10. At S26, controller 21 turns off the power supply to valve open electromagnet 10. At S27, the same control as that at S24 (specifically, S31 through S37) are carried out for valve closure electromagnet 11.

[0080] It is noted that S34 through S37 correspond to a second current supply control section.

[0081] As described hereinabove, in the initialization control during the engine start in the preferred embodiment, the power supply current is feedback controlled and the setting of the excessively large control gain G1 can be avoided. Hence, movable element 6 can be driven by the appropriate electro-magnetic force. As movable element 6 becomes approached to the attracted side electromagnet, the deceleration of movable element can be carried out. Therefore, the stable initialization even under the low temperature region can be achieved and the power consumption can be suppressed at minimum.

[0082] In addition, since control gain G1 when the initialization has succeeded is set continuously until the engine temperature becomes ordinary temperature, a reliable control gain G2 can effectively be carried out and the control apparatus for the electromagnetically operable engine valve can contribute to the minimization of the reductions of noise and power consumption.

[0083] It is noted that each of the pair of electromagnets 10 and 11 includes a coil portion and a magnetic core portion, both portions being formed about guide axle member 7 in a bobbin form and surfaces thereof being faced against movable element 6, each of the pair of electromagnets 10 or 11 on which movable element 6 is attracted and moved is constituted by an electromagnet unit defined in the claims, the engine lubricating oil is circulated in housing 100 shown in Fig. 1A, an electromagnetically operable engine valve assembly includes the control apparatus described above, and engine valve body 3 shown in Fig. 1A indicates the neutral position.

[0084] Although the invention has been described above by reference to certain embodiment of the invention, the invention is not limited to the embodiments described above. Modifications and variations of the embodiments described above will occur to those skilled in the art in the light of the above teachings. The scope of the invention is defined with reference to the following claims.

Claims

1. Electromagnetically operable engine valve assembly for an internal combustion engine, comprising:

a movable element (6);

a spring element (5, 9) to bias the movable element (6) at a neutral position;

an electromagnet unit (10, 11) faced against the movable element (6);

a control apparatus (21) to control a current (i) supplied to the electromagnet unit (10, 11) to drive the movable element (6) so as to regulate a displacement of a valve body (3) associated with the movable element (6), the control apparatus (21) comprising:

an initialization control section and a position detector (31) enabled to detect a position (z) of the movable element (6) with respect to the electromagnet unit (10, 11),

wherein the initialization control section executes an initialization control such that the current (i) is continuously supplied to the electromagnet unit (10, 11) to move the movable element (6) rested at the neutral position to an initial position, and

wherein means are provided for a repetition of the execution of continuous current supply controls with interruption of the continuous current supply between each of them, only the last one of which being suitable for bringing the moveable element (6) in the initial position,

characterized in that the control apparatus further comprises

a first current supply control section that performs a feedback control of the current (i) supplied to the electromagnet unit (10, 11) during the execution of the initialization control by a feedback control gain (G1) on the basis of the position (z) of the movable element (6) detected by the position detector (31); and

a feedback control gain varying section that varies the feedback control gain (G1) in such a manner that as the movable element (6) becomes nearer to the initial position, a velocity (v) of the movable element (6) to arrive at the initial position becomes reduced when the initialization control section executes the initialization control repeatedly until the initialization control has succeeded in moving the movable element (6) to the initial position during an engine start.

2. Electromagnetically operable engine valve assembly according to claim 1, characterized in that the feedback control gain varying section comprises a feedback control gain switching section that switches the feedback control gain (G1) from an initial value(G1₁) near to zero or zero gradually to a value larger than the initial value(G1₁) and to a degree such as to decelerate and land the movable element (6) onto the electromagnet unit (10, 11) for each execution of initialization control by the initialization control section until the initialization control has succeeded in moving the movable element (6) to the initial position.

3. Electromagnetically operable engine valve assembly according to claim 1, characterized in that the initialization control section executes the initialization control during the engine start under a temperature of the engine lower than a predetermined value.

4. Electromagnetically operable engine valve assembly according to claim 3, characterized in that the control apparatus further comprises a second current supply control section that executes the feedback control for the current supplied to the electromagnet unit (10, 11) during an ordinary drive of the engine on the basis of the position (z) of the movable element (6) detected by the position detector (31) and wherein the feedback control gain (G1) set in the first current supply control section is set in the second current control section until the engine temperature indicates an ordinary temperature.

5. Electromagnetically operable engine valve assembly according to claim 2, characterized in that the feedback control gain switching section switches the feedback control gain (G1) to be incremented by a constant quantity.

6. Electromagnetically operable engine valve assembly according to claim 1, characterized in that the feedback control gain varying section comprises a feedback control gain switching section that switches the feedback control gain (G1) in such a manner that its increment rate is gradually decreased from an initial increment rate (ΔG) which is relatively large whenever the initialization control is executed.

7. Electromagnetically operable engine valve assembly according to claim 6, characterized in that the feedback control gain (G1) is increased in accordance with an un-arrival distance (d_n-1) to the initial position of the movable element (6) by a previously proposed initialization control.

8. Electromagnetically operable engine valve assembly according to claim 6, characterized in that the feedback control gain (G1) is increased in accordance with the initial position of the movable element (6) by a previously executed initialization control.

9. Electromagnetically operable engine valve assembly according to claim 6, characterized in that the feedback control gain (G1) is increased in accordance with a magnitude of a logarithm of a value based on the number of times (n) the initialization control has been executed.

10. Electromagnetically operable engine valve assembly according to claim 1, characterized in that the spring element comprises a pair of springs (5, 9), one of the pair of springs (9) biasing the movable element (6) toward a valve open direction and the other of the pair of springs (5) biasing the movable element (6) toward a valve closure direction, the electromagnet unit comprises a pair of valve open and valve closure electromagnets (10, 11), the movable element (6) being intervened between the pair of valve open and valve closure electromagnets (10, 11), and wherein the initial position of the movable element (6) at which the movable element(6) is to be moved during the execution of the initialization corresponds to a position of one of the pair of valve open and valve closure electromagnets (10, 11) at which the movable element (6) is attracted and landed.

11. Electromagnetically operable engine valve assembly according to claim 10, characterized by a coolant temperature sensor (32) to detect a coolant temperature (Tw) of the engine, wherein the controller further comprises a first determining section to determine whether the detected coolant temperature (Tw) is equal to or below a predetermined value of temperature (To), and wherein the initialization control section executes the initialization control according to a result of determination that the detected coolant temperature (Tw) is equal to or below the predetermined value of temperature (To).

12. Electromagnetically operable engine valve assembly according to claim 11, characterized in that the control apparatus further comprises a second determining section that determines if the movable element (6) is returned to the neutral position on the basis of the detected position (z) of the movable element (6) and wherein the feedback control gain varying section varies the feedback control gain G1_n as follows: G1_n = G1_n-1 + ΔG, wherein G1_n-1 denotes a previously set feedback control gain and ΔG denotes a predetermined gain increment according to a result of determination by the second determining section that the movable element (6) is returned to the neutral position.

13. Electromagnetically operable engine valve assembly according to claim 11, characterized in that the control apparatus further comprises a second determining section that determines if the movable element (6) is returned to the neutral position on the basis of the detected position (z) of the movable element (6) and wherein the feedback control gain varying section varies the feedback control gain G1_n as follows: G1_n = G1_n-1 + α x d_n-1, wherein α denotes a constant and d_n-1 denotes a previous un-arrival distance, according to a result of determination by the second determining section that the movable element (6) is returned to the neutral position.

14. Electromagnetically operable engine valve assembly according to claim 11, characterized in that the control apparatus further comprises a second determining section that determines if the movable element (6) is returned to the neutral position on the basis of the detected position (z) of the movable element (6) and wherein the feedback control gain varying section varies the feedback control gain G1_n as follows: G1_n = β x n^1/m, wherein β denotes a constant, n denotes the number of times the initialization control has been executed, and m denotes a constant , according to a result of determination by the second determining section that the movable element (6) is returned to the neutral position.

15. Electromagnetically operable engine valve assembly according to claim 11, characterized in that the control apparatus further comprises a second determining section that determines if the movable element (6) is returned to the neutral position on the basis of the detected position (z) of the movable element (6) and wherein the feedback control gain varying section varies the feedback control gain G1_n as follows: G1_n = ε x log_a (n+1), wherein ε denotes a constant, and n denotes the number of times the initialization control has been executed according to a result of determination by the second determining section that the movable element (6) is returned to the neutral position.

16. Electromagnetically operable engine valve assembly according to claim 15, characterized in that the feedback control gain varying section varies the feedback control gain G1_n as follows: G1_n = ε x ln(n+1) according to a result of determination by the second determining section that the movable element (6) is returned to the neutral position.

17. An electromagnetically operable engine valve assembly for an internal combustion engine, comprising:

a movable element (6);

a pair of springs (5, 9) to bias the movable element (6) at a neutral position;

a pair of electromagnets (10, 11), each electromagnet (10, 11) being faced against the movable element (6);

a control apparatus (21) to control a current (i) supplied to one of the pair of electromagnets (10, 11) to drive the movable element (6) so as to regulate a displacement of a valve body (3) associated with the movable element (6), the control apparatus comprising:

an initialization control section and a position detector (31) enabled to detect a position (z) of the movable element (6) with respect to one of the pair of electromagnets (10, 11);

wherein the initialization control section executes an initialization control such that the current (i) is continuously supplied to one of the pair of electromagnets (10, 11) to move the movable element (6) rested at the neutral position to an initial position; and wherein means are provided for a repetition of the execution of continuous current supply controls with interruption of the continuous current supply between each of them, only the last one of which being suitable for bringing the moveable element (6) in the initial position,

characterized in that the controller (21) further comprises a first current supply control section that performs a feedback control of the current (i) supplied to one of the pair of electromagnets (10, 11) during the execution of the initialization control by a feedback control gain (G1) on the basis of the position (z) of the movable element (6) detected by the position detector (31); and

a feedback control gain switching section that switches the feedback control gain (G1) in such a manner that as the movable element (6) becomes nearer to the initial position, a velocity (v) of the movable element (6) to arrive at the initial position becomes reduced when the initialization control section executes the initialization control repeatedly until the initialization control has succeeded in moving the movable element (6) to the initial position during an engine start.

18. A method applicable to an electromagnetically operable engine valve assembly in an internal combustion engine, the electromagnetically operable engine valve assembly comprising:

a movable element (6);

a spring element (5, 9) to bias the movable element (6) at a neutral position;

an electromagnet unit (10, 11) faced against the movable element (6); and

a control apparatus (21) to control a current (i) supplied to the electromagnet unit (10, 11) to drive the movable element (6) so as to regulate a displacement of a valve body (3) associated with the movable element (6), and the method comprising:

executing an initialization control such that the current (i) is continuously supplied to the electromagnet unit (10, 11) to move the movable element (6) rested at the neutral position to an initial position;

repeating the execution of continuous current supply controls with interruption of the continuous current supply between each of them;

bringing the moveable element (6) in the initial position by only the last one of the continuous current supply controls; and

detecting a position (z) of the movable element (6) with respect to the electromagnet unit (10,11), characterized by

performing a feedback control of the current (i) supplied to the electromagnet unit (10, 11) during the execution of the initialization control by a feedback control gain (G1) on the basis of the detected position (z) of the movable element (6);

varying the feedback control gain (G1) in such a manner that as the movable element (6) becomes nearer to the initial position, a velocity (v) of the movable element(6) to arrive at the initial position becomes reduced when executing the initialization control repeatedly until the initialization control has succeeded in moving the movable element (6) to the initial position during an engine start.

Ansprüche

1. Elektromagnetisch zu betätigende Motorventilanordnung für einen Verbrennungsmotor, die umfasst:

ein bewegliches Element (6);

ein Federelement (5, 9), das das bewegliche Element (6) an eine neutrale Position spannt;

eine Elektromagneteinheit (10, 11), die dem beweglichen Element (6) gegenüberliegt;

eine Steuervorrichtung (21), die einen der Elektromagneteinheit (10, 11) zugeführten Strom (i) steuert, um das bewegliche Element (6) so anzusteuern, dass eine Verschiebung eines mit dem beweglichen Element (6) verbundenen Ventilkörpers (3) reguliert wird, wobei die Steuervorrichtung (21) umfasst:

einen Initialisierungs-Steuerabschnitt und einen Positionsdetektor (31), der in der Lage ist, eine Position (z) des beweglichen Elementes (6) in Bezug auf die Elektromagneteinheit (10, 11) zu erfassen,

wobei der Initialisierungs-Steuerabschnitt eine Initialisierungssteuerung so ausführt, dass der Strom (i) der Elektromagneteinheit (10, 11) kontinuierlich zugeführt wird, um das bewegliche Element (6), das an der neutralen Position ruht, an eine Ausgangsposition zu bewegen, und wobei eine Einrichtung zum Wiederholen der Ausführung kontinuierlicher Stromzuführ-Steuervorgänge mit Unterbrechung der kontinuierlichen Stromzufuhr zwischen jedem von ihnen vorhanden ist und nur der letzte von ihnen dazu geeignet ist, das bewegliche Element (6) in die Ausgangsposition zu bringen,

dadurch gekennzeichnet, dass die Steuervorrichtung des Weiteren umfasst:

einen ersten Stromzufuhr-Steuerabschnitt, der eine Regelung des der Elektromagneteinheit (10, 11) zugeführten Stroms (i) während der Ausführung der Initialisierungssteuerung mit einer Regelungsverstärkung (G1) auf Basis der durch den Positionsdetektor (31) erfassten Position (z) des beweglichen Elementes (6) durchführt; und

einen Regelungsverstärkungs-Variierabschnitt, der die Regelungsverstärkung (G1) so variiert, dass, wenn das bewegliche Element (6) näher an die Ausgangsposition kommt, eine Geschwindigkeit (v) des beweglichen Elementes (6) zum Erreichen der Ausgangsposition reduziert wird, wenn der Initialisierungs-Steuerabschnitt die Initialisierungssteuerung wiederholt ausführt, bis die Initialisierungssteuerung das bewegliche Element (6) während eines Motorstarts erfolgreich an die Ausgangsposition bewegt hat.

2. Elektromagnetisch zu betätigende Motorventilanordnung nach Anspruch 1, dadurch gekennzeichnet, dass der Regelungsverstärkungs-Varüerabschnitt einen Regelungsverstärkungs-Umstellabschnitt umfasst, der die Regelungsverstärkung (G1) von einem Ausgangswert (G1₁) von Null oder nahe Null allmählich auf einen größeren Wert als den Ausgangswert (G1₁) und in einem Grad, durch den das bewegliche Element (6) abgebremst und auf die Elektromagneteinheit (10, 11) aufgesetzt wird, für jede Ausführung von Initialisierungssteuerung durch den Initialisierungs-Steuerabschnitt umstellt, bis die Initialisierungssteuerung das bewegliche Element (6) erfolgreich an die Ausgangsposition bewegt hat.

3. Elektromagnetisch zu betätigende Motorventilanordnung nach Anspruch 1, dadurch gekennzeichnet, dass der Initialisierungs-Steuerabschnitt die Initialisierungssteuerung während des Motorstarts bei einer Temperatur des Motors unter einem vorgegebenen Wert ausführt.

4. Elektromagnetisch zu betätigende Motorventilanordnung nach Anspruch 3, dadurch gekennzeichnet, dass die Steuervorrichtung des Weiteren einen zweiten Stromzuführ-Steuerabschnitt umfasst, der die Regelung für den der Elektromagneteinheit (10, 11) zugeführten Strom während eines normalen Antriebs des Motors auf Basis der durch den Positionsdetektor (31) erfassten Position (z) des beweglichen Elementes (6) ausführt, und wobei die in dem ersten Stromzufuhr-Steuerabschnitt eingestellte Regelungsverstärkung (G1) in dem zweiten Strom-Steuerabschnitt eingestellt wird, bis die Motortemperatur eine normale Temperatur anzeigt.

5. Elektromagnetisch zu betätigende Motorventilanordnung nach Anspruch 2, dadurch gekennzeichnet, dass der Regelungsverstärkungs-Umstellabschnitt die Regelungsverstärkung (G1) so umstellt, dass sie um ein konstantes Maß gesteigert wird.

6. Elektromagnetisch zu betätigende Motorventilanordnung nach Anspruch 1, dadurch gekennzeichnet, dass der Regelungsverstärkungs-Variierabschnitt einen Regelungsverstärkungs-Umstellabschnitt umfasst, der die Regelungsverstärkung (G1) so umstellt, dass ihre Steigerungsrate von einer anfänglichen Steigerungsrate (ΔG), die relativ groß ist, immer dann allmählich verringert wird, wenn die Initialisierungssteuerung ausgeführt wird.

7. Elektromagnetisch zu betätigende Motorventilanordnung nach Anspruch 6, dadurch gekennzeichnet, dass die Regelungsverstärkung (G1) gemäß einem Nichterreichungs-Abstand (d_n-1) zu der Ausgangsposition des beweglichen Elementes (6) durch eine zuvor vorgeschlagene Initialisierungssteuerung erhöht wird.

8. Elektromagnetisch zu betätigende Motorventilanordnung nach Anspruch 6, dadurch gekennzeichnet, dass die Regelungsverstärkung (G1) gemäß der Ausgangsposition des beweglichen Elementes (6) durch eine zuvor ausgeführte Initialisierungssteuerung erhöht wird.

9. Elektromagnetisch zu betätigende Motorventilanordnung nach Anspruch 6, dadurch gekennzeichnet, dass die Regelungsverstärkung (G1) gemäß einem Betrag eines Logarithmus eines Wertes erhöht wird, der auf der Häufigkeit (n) der Ausführung der Initialisierungssteuerung basiert.

10. Elektromagnetisch zu betätigende Motorventilanordnung nach Anspruch 1, dadurch gekennzeichnet, dass das Federelement ein Paar Federn (5, 9) umfasst, wobei eine des Paars Federn (9) das bewegliche Element (6) in eine VentilÖffnungsrichtung spannt und die andere des Paars Federn (9) das bewegliche Element (6) in eine Ventil-Verschlussrichtung spannt, die elektromagnetische Einheit ein Paar Ventilöffnungs-und-Ventilverschluss-Elektromagnete (10, 11) umfasst, das bewegliche Element (6) zwischen dem Paar Ventilöffnungs-und-Ventilverschluss-Elektromagnete (10, 11) angeordnet ist, und wobei die Ausgangsposition des beweglichen Elementes (6), an die das bewegliche Element (6) während der Ausführung der Initialisierung zu bewegen ist, einer Position eines des Paars Ventilöffnungs-und-Ventilverschluss-Elektromagnete (10, 11) entspricht, an der das bewegliche Element (6) angezogen und aufgesetzt wird.

11. Elektromagnetisch zu betätigende Motorventilanordnung nach Anspruch 10, gekennzeichnet durch einen Kühlmitteltemperatur-Sensor (32), der eine Kühlmitteltemperatur (Tw) des Motors erfasst, wobei die Steuervorrichtung des Weiteren einen ersten Feststellabschnitt umfasst, der feststellt, ob die erfasste Kühlmitteltemperatur (Tw) einem vorgegebenen Wert der Temperatur (T0) gleich ist oder darunter liegt, und wobei der Initialisierungs-Steuerabschnitt die Initialisierungssteuerung gemäß einem Ergebnis der Feststellung ausführt, dass die erfasste Kühlmitteltemperatur (Tw) dem vorgegebenen Wert der Temperatur (T0) gleich ist oder darunter liegt.

12. Elektromagnetisch zu betätigende Motorventilanordnung nach Anspruch 11, dadurch gekennzeichnet, dass die Steuervorrichtung des Weiteren einen zweiten Feststellabschnitt umfasst, der auf Basis der erfassten Position (z) des beweglichen Elementes (6) feststellt, ob das bewegliche Element (6) an die neutrale Position zurückgeführt ist, und wobei der Regelungsverstärkungs-Variierabschnitt gemäß einem Ergebnis der Feststellung durch den zweiten Feststellabschnitt, dass das bewegliche Element (6) an die neutrale Position zurückgeführt ist, die Regelungsverstärkung G1_n wie folgt variiert:

G1_n = G1_n-1 + ΔG, wobei G1_n-1 eine im voraus festgelegte Regelungsverstärkung und ΔG eine vorgegebene Verstärkungssteigerung bezeichnet.

13. Elektromagnetisch zu betätigende Motorventilanordnung nach Anspruch 11, dadurch gekennzeichnet, dass die Steuervorrichtung des Weiteren einen zweiten Feststellabschnitt umfasst, der auf Basis der erfassten Position (z) des beweglichen Elementes feststellt, ob das bewegliche Element (6) an die neutrale Position zurückgeführt ist, und wobei der Regelungsverstärkungs-Variierabschnitt gemäß einem Ergebnis der Feststellung durch den zweiten Feststellabschnitt, dass das bewegliche Element (6) an die neutrale Position zurückgeführt ist, die Regelungsverstärkung G1_n wie folgt variiert:

G1_n = G1_n-1 + α x d_n-1, wobei α eine Konstante bezeichnet und d_n-1 einen vorangehenden Nichterreichungs-Abstand bezeichnet.

14. Elektromagnetisch zu betätigende Motorventilanordnung nach Anspruch 11, dadurch gekennzeichnet, dass die Steuervorrichtung des Weiteren einen zweiten Feststellabschnitt umfasst, der auf Basis der erfassten Position (z) des beweglichen Elementes (6) feststellt, ob das bewegliche Element (6) an die neutrale Position zurückgeführt ist, und wobei der Regelungsverstärkungs-Varüerabschnitt gemäß einem Ergebnis der Feststellung durch den zweiten Feststellabschnitt, dass das bewegliche Element (6) an die neutrale Position zurückgeführt ist, die Regelungsverstärkung G1_n wie folgt variiert:

G1_n = β x n^1/m, wobei β eine Konstante bezeichnet, n die Häufigkeit der Ausführung der Initialisierungssteuerung bezeichnet und m eine Konstante bezeichnet.

15. Elektromagnetisch zu betätigende Motorventilanordnung nach Anspruch 11, dadurch gekennzeichnet, dass die Steuervorrichtung des Weiteren einen zweiten Feststellabschnitt umfasst, der auf Basis der erfassten Position (z) des beweglichen Elementes (6) feststellt, ob das bewegliche Element (6) an die neutrale Position zurückgeführt ist, und wobei der Regelungsverstärkungs-Variierabschnitt gemäß einem Ergebnis der Feststellung durch den zweiten Feststellabschnitt, dass das bewegliche Element (6) an die neutrale Position zurückgeführt ist, die Regelungsverstärkung G1_n wie folgt variiert:

G1_n = ε x log_a (n+1), wobei ε eine Konstante bezeichnet und n die Häufigkeit der Ausführung der Initialisierungssteuerung bezeichnet.

16. Elektromagnetisch zu betätigende Motorventilanordnung nach Anspruch 15, dadurch gekennzeichnet, dass der Regelungsverstärkungs-Variierabschnitt die Regelungsverstärkung G1_n gemäß einem Ergebnis der Feststellung durch den zweiten Feststellabschnitt, dass das bewegliche Element (6) an die neutrale Position zurückgeführt ist, wie folgt variiert:

17. Elektromagnetisch zu betätigende Motorventilanordnung für einen Verbrennungsmotor, die umfasst:

ein bewegliches Element (6);

ein Paar Federn (5, 9), die das bewegliche Element (6) an eine neutrale Position spannen;

ein Paar Elektromagnete (10, 11), wobei jeder Elektromagnet (10, 11) dem beweglichen Element (6) gegenüberliegt;

eine Steuervorrichtung (21), die einen einem des Paars von Elektromagneten (10, 11) zugeführten Strom (i) steuert, um das bewegliche Element (6) so anzusteuern, dass eine Verschiebung eines mit dem beweglichen Element (6) verbundenen Ventilkörpers (3) reguliert wird, wobei die Steuervorrichtung umfasst:

einen Initialisierungs-Steuerabschnitt und einen Positionsdetektor (31), der in der Lage ist, eine Position (z) des beweglichen Elementes (6) in Bezug auf einen des Paars von Elektromagneten (10, 11) zu erfassen;

wobei der Initialisierungs-Steuerabschnitt eine Initialisierungssteuerung so ausführt, dass der Strom (i) einem des Paars von Elektromagneten (10, 11) kontinuierlich zugeführt wird, um das bewegliche Element (6), das an der neutralen Position ruht, an eine Ausgangsposition zu bewegen, und wobei eine Einrichtung zum Wiederholen der Ausführung kontinuierlicher Stromzuführ-Steuervorgänge mit Unterbrechung der kontinuierlichen Stromzufuhr zwischen jedem von ihnen vorhanden ist und nur der letzte von ihnen dazu geeignet ist, das bewegliche Element (6) in die Ausgangsposition zu bringen, dadurch gekennzeichnet, dass die Steuervorrichtung (21) des Weiteren einen ersten Stromzufuhr-Steuerabschnitt umfasst, der eine Regelung des dem einen des Paars von Elektromagneten (10, 11) zugeführten Stroms (i) während der Ausführung der Initialisierungssteuerung mit einer Regelungsverstärkung (G1) auf Basis der durch den Positionsdetektor (31) erfassten Position (z) des beweglichen Elementes (6) durchführt; und

einen Regelungsverstärkungs-Umstellabschnitt, der die Regelungsverstärkung (G1) so umstellt, dass, wenn das bewegliche Element (6) näher an die Ausgangsposition kommt, eine Geschwindigkeit (v) des beweglichen Elementes (6) zum Erreichen der Ausgangsposition reduziert wird, wenn der Initialisierungs-Steuerabschnitt die Initialisierungssteuerung wiederholt ausführt, bis die Initialisierungssteuerung das bewegliche Element (6) während eines Motorstarts erfolgreich an die Ausgangsposition bewegt hat.

18. Verfahren, das bei einer elektromagnetisch zu betätigenden Motorventilanordnung in einem Verbrennungsmotor eingesetzt werden kann, wobei die elektromagnetisch zu betätigende Motorventilanordnung umfasst:

ein bewegliches Element (6);

ein Federelement (5, 9), das das bewegliche Element (6) an eine neutrale Position spannt;

eine Elektromagneteinheit (10, 11), die dem beweglichen Element (6) gegenüberliegt; und

eine Steuervorrichtung (21), die einen der Elektromagneteinheit (10, 11) zugeführten Strom (i) steuert, um das bewegliche Element (6) so anzusteuern, dass eine Verschiebung eines mit dem beweglichen Element (6) verbundenen Ventilkörpers (3) reguliert wird, und wobei das Verfahren umfasst:

Ausführen einer Initialisierungssteuerung, so dass der Strom (i) der Elektromagneteinheit (10, 11) kontinuierlich zugeführt wird, um das bewegliche Element (6), das an der neutralen Position ruht, an eine Ausgangsposition zu bewegen;

Wiederholen der Ausführung kontinuierlicher Stromzuführ-Steuervorgänge mit Unterbrechung der kontinuierlichen Stromzufuhr zwischen jedem von ihnen;

Bringen des beweglichen Elementes (6) in die Ausgangsposition mit lediglich dem letzten der kontinuierlichen Stromzuführ-Steuervorgänge; und

Erfassen einer Position (z) des beweglichen Elementes (6) in Bezug auf die Elektromagneteinheit (10, 11), gekennzeichnet durch

Durchführen einer Regelung des der der Elektromagneteinheit (10, 11) zugeführten Stroms (i), während der Ausführung der Initialisierungssteuerung mit einer Regelungsverstärkung (G1) auf Basis der erfassten Position (z) des beweglichen Elementes (6);

Variieren der Regelungsverstärkung (G1) so, dass, wenn das bewegliche Element (6) näher an die Ausgangsposition kommt, eine Geschwindigkeit (v) des beweglichen Elementes (6) zum Erreichen der Ausgangsposition reduziert wird, wenn die Initialisierungssteuerung wiederholt ausgeführt wird, bis die Initialisierungssteuerung das bewegliche Element (6) während eines Motorstarts erfolgreich an die Ausgangsposition bewegt hat.

Revendications

1. Arrangement de soupapes électromagnétiques de moteur destiné à un moteur à combustion interne, comprenant:

un élément mobile (6);

un élément de ressort (5, 9) destiné à incliner l'élément mobile (6) dans une position neutre;

une unité d'électroaimant (10, 11) tournée contre l'élément mobile (6);

un appareil de commande (21) destiné à commander un courant (i) fourni à l'unité d'électroaimant (10, 11) afin d'entraîner l'élément mobile (6) de façon à réguler un déplacement d'un corps de soupape (3) associé à l'élément mobile (6), l'appareil de commande (21) comprenant:

une section de commande d'initialisation et un détecteur de position (31) permettant de détecter une position (z) de l'élément mobile (6) par rapport à l'unité d'électroaimant (10, 11),

dans lequel la section de commande d'initialisation exécute une commande d'initialisation de telle sorte que le courant (i) soit fourni en continu à l'unité d'électroaimant (10, 11) afin de déplacer l'élément mobile (6) placé dans la position neutre dans une position initiale, et dans lequel des moyens sont prévus afin de répéter l'exécution des commandes de fourniture de courant en continu avec une interruption de la fourniture de courant en continu entre chacun d'entre elles, seul le dernier étant capable d'amener l'élément mobile (6) dans la position initiale,

caractérisé en ce que l'appareil de commande comprend en outre

une première section de commande de fourniture de courant qui effectue un asservissement du courant (i) fourni à l'unité d'électroaimant (10, 11) pendant l'exécution de la commande d'initialisation par un gain d'asservissement (G1) sur la base de la position (z) de l'élément mobile (6) détectée par le détecteur de position (31); et

une section de variation de gain d'asservissement qui fait varier le gain d'asservissement (G1) de telle sorte que, lorsque l'élément mobile (6) se rapproche de la position initiale, une vitesse (v) de l'élément mobile (6) arrivant au niveau de la position initiale soit réduite lorsque la section de commande d'initialisation exécute la commande d'initialisation de manière répétée jusqu'à ce que la commande d'initialisation ait réussi à déplacer l'élément mobile (6) dans la position initiale pendant un démarrage du moteur.

2. Arrangement de soupapes électromagnétiques de moteur selon la revendication 1, caractérisé en ce que la section de variation de gain d'asservissement comprend une section d'activation de gain d'asservissement qui fait passer progressivement le gain d'asservissement (G1) d'une valeur initiale (G1_n) proche de zéro ou nulle à une valeur supérieure à la valeur initiale (G1_n) et jusqu'à un degré permettant de décélérer et d'abaisser l'élément mobile (6) sur l'unité d'électroaimant (10, 11) pour chaque exécution de la commande d'initialisation par la section de commande d'initialisation jusqu'à ce que la commande d'initialisation ait réussi à déplacer l'élément mobile (6) dans la position initiale.

3. Arrangement de soupapes électromagnétiques de moteur selon la revendication 1, caractérisé en ce que la section de commande d'initialisation exécute la commande d'initialisation pendant le démarrage du moteur avec une température du moteur inférieure à une valeur prédéterminée.

4. Arrangement de soupapes électromagnétiques de moteur selon la revendication 3, caractérisé en ce que l'appareil de commande comprend en outre une seconde section de commande de fourniture de courant qui exécute l'asservissement du courant fourni à l'unité d'électroaimant (10, 11) pendant un entraînement ordinaire du moteur sur la base de la position (z) de l'élément mobile (6) détectée par le détecteur de position (31), et dans lequel le gain d'asservissement (G1) défini dans la première section de commande de fourniture de courant est défini dans la seconde section de commande de courant jusqu'à ce que la température du moteur indique une température ordinaire.

5. Arrangement de soupapes électromagnétiques de moteur selon la revendication 2, caractérisé en ce que la section d'activation de gain d'asservissement active le gain d'asservissement (G1) afin qu'il soit augmenté selon une quantité constante.

6. Arrangement de soupapes électromagnétiques de moteur selon la revendication 1, caractérisé en ce que la section de variation de gain d'asservissement comprend une section d'activation de gain d'asservissement qui active le gain d'asservissement (G1) de telle sorte que sa vitesse d'augmentation soit progressivement réduite par rapport à une vitesse d'augmentation initiale (ΔG) qui est relativement élevée lorsque la commande d'initialisation est exécutée.

7. Arrangement de soupapes électromagnétiques de moteur selon la revendication 6, caractérisé en ce que le gain d'asservissement (G1) est augmenté selon une distance de non-arrivée (d_n-1) dans la position initiale de l'élément mobile (6) par une commande d'initialisation précédemment proposée.

8. Arrangement de soupapes électromagnétiques de moteur selon la revendication 6, caractérisé en ce que le gain d'asservissement (G1) est augmenté selon la position initiale de l'élément mobile (6) par une commande d'initialisation précédemment exécutée.

9. Arrangement de soupapes électromagnétiques de moteur selon la revendication 6, caractérisé en ce que le gain d'asservissement (G1) est réduit selon une magnitude d'un logarithme d'une valeur basée sur le nombre de fois (n) où la commande d'initialisation a été exécutée.

10. Arrangement de soupapes électromagnétiques de moteur selon la revendication 1, caractérisé en ce que l'élément de ressort comprend une paire de ressorts (5, 9), l'un de la paire de ressorts (9) inclinant l'élément mobile (6) vers une direction d'ouverture de soupape et l'autre de la paire de ressorts (5) inclinant l'élément mobile (6) vers une direction de fermeture de soupape, l'unité d'électroaimant comprend une paire d'électroaimants d'ouverture de soupape et de fermeture de soupape (10, 11), l'élément mobile (6) étant placé entre la paire d'électroaimants d'ouverture de soupape et de fermeture de soupape (10, 11), et dans lequel la position initiale de l'élément mobile (6) dans laquelle l'élément mobile (6) doit être déplacé pendant l'exécution de l'initialisation correspond à une position de l'un de la paire d'électroaimants d'ouverture de soupape et de fermeture de soupape (10, 11) dans laquelle l'élément mobile (6) est attiré ou abaissé.

11. Arrangement de soupapes électromagnétiques de moteur selon la revendication 10, caractérisé par un capteur de température de liquide de refroidissement (32) destiné à détecter une température de liquide de refroidissement (Tw) du moteur, dans lequel le contrôleur comprend en outre une première section de détermination destinée à déterminer si la température détectée du liquide de refroidissement (Tw) est égale ou inférieure à une valeur prédéterminée de température (To), et dans lequel la section de commande d'initialisation exécute la commande d'initialisation selon un résultat de la détermination selon lequel la température détectée du liquide de refroidissement (Tw) est égale ou inférieure à la valeur de température prédéterminée (To).

12. Arrangement de soupapes électromagnétiques de moteur selon la revendication 11, caractérisé en ce que l'appareil de commande comprend en outre une seconde section de détermination qui détermine si l'élément mobile (6) est renvoyé vers la position neutre sur la base de la position détectée (z) de l'élément mobile (6), et dans lequel la section de variation de gain d'asservissement fait varier le gain d'asservissement G1_n comme suit: G1_n = G1_n-1 + ΔG, où G1_n-1 représente un gain d'asservissement précédemment défini et ΔG représente une augmentation de gain prédéterminée selon un résultat de détermination par la seconde section de détermination selon lequel l'élément mobile (6) est retourné dans la position neutre.

13. Arrangement de soupapes électromagnétiques de moteur selon la revendication 11, caractérisé en ce que l'appareil de commande comprend en outre une seconde section de détermination qui détermine si l'élément mobile (6) est retourné dans la position neutre sur la base de la position détectée (z) de l'élément mobile (6), et dans lequel la section de variation de gain d'asservissement fait varier le gain d'asservissement G1_n comme suit: G1_n = G1_n-1 + α x d_n-1, où α représente une constante et d_n-1 représente une distance de non-arrivée précédente, selon un résultat de détermination par la seconde section de détermination selon lequel l'élément mobile (6) est retourné dans la position neutre.

14. Arrangement de soupapes électromagnétiques de moteur selon la revendication 11, caractérisé en ce que l'appareil de commande comprend en outre une seconde section de détermination qui détermine si l'élément mobile (6) est retourné dans la position neutre sur la base de la position détectée (z) de l'élément mobile (6), et dans lequel la section de variation de gain d'asservissement fait varier le gain d'asservissement G1_n comme suit: β x n^1/m, où β représente une constante, n représente le nombre de fois où la commande d'initialisation a été exécutée, et m représente une constante, selon un résultat de détermination par la seconde section de détermination selon lequel l'élément mobile (6) est retourné dans la position neutre.

15. Arrangement de soupapes électromagnétiques de moteur selon la revendication 11, caractérisé en ce que l'appareil de commande comprend en outre une seconde section de détermination qui détermine si l'élément mobile (6) est retourné dans la position neutre sur la base de la position détectée (z) de l'élément mobile (6), et dans lequel la section de variation de gain d'asservissement fait varier le gain d'asservissement G1_n comme suit: G1_n = ε x log_a (n+1), où ε représente une constante, et n représente le nombre de fois où la commande d'initialisation a été exécutée selon un résultat de détermination par la seconde section de détermination selon lequel l'élément mobile (6) est retourné dans la position neutre.

16. Arrangement de soupapes électromagnétiques de moteur selon la revendication 15, caractérisé en ce que la section de variation de gain d'asservissement fait varier le gain d'asservissement G1_n comme suit: G1_n = ε x In(n+1) selon un résultat de détermination par la seconde section de détermination selon lequel l'élément mobile (6) est retourné dans la position neutre.

17. Arrangement de soupapes électromagnétiques de moteur destiné à un moteur à combustion interne, comprenant:

un élément mobile (6);

une paire de ressorts (5, 9) destinés à incliner l'élément mobile (6) dans une position neutre;

une paire d'électroaimants (10, 11), chaque électroaimant (10, 11) étant tourné contre l'élément mobile (6);

un appareil de commande (21) destiné à commander un courant (i) fourni à l'un de la paire d'électroaimants (10, 11) afin d'entraîner l'élément mobile (6) de façon à réguler un déplacement d'un corps de soupape (3) associé à l'élément mobile (6), l'appareil de commande comprenant:

une section de commande d'initialisation et un détecteur de position (31) permettant de détecter une position (z) de l'élément mobile (6) par rapport à l'un de la paire d'électroaimants (10, 11);

dans lequel la section de commande d'initialisation exécute une commande d'initialisation de telle sorte que le courant (i) soit fourni en continu à l'un de la paire d'électroaimants (10, 11) afin de déplacer l'élément mobile (6) placé dans la position neutre vers une position initiale;

et dans lequel des moyens sont prévus afin de répéter l'exécution des commandes de fourniture de courant en continu avec une interruption de la fourniture de courant en continu entre chacun d'entre elles, seul le dernier étant capable d'amener l'élément mobile (6) dans la position initiale,

caractérisé en ce que le contrôleur (21) comprend en outre une première section de commande de fourniture de courant qui effectue un asservissement du courant (i) fourni à l'un de la paire d'électroaimants (10, 11) pendant l'exécution de la commande d'initialisation par un gain d'asservissement (G1) sur la base de la position (z) de l'élément mobile (6) détectée par le détecteur de position (31); et

une section d'activation de gain d'asservissement qui active le gain d'asservissement (G1) de telle sorte que, lorsque l'élément mobile (6) se rapproche de la position initiale, une vitesse (v) de l'élément mobile (6) arrivant au niveau de la position initiale soit réduite lorsque la section de commande d'initialisation exécute la commande d'initialisation de manière répétée jusqu'à ce que la commande d'initialisation ait réussi à déplacer l'élément mobile (6) dans la position initiale pendant un démarrage du moteur.

18. Procédé applicable à un arrangement de soupapes électromagnétiques de moteur dans un moteur à combustion interne, l'arrangement de soupapes électromagnétiques de moteur comprenant:

un élément mobile (6);

un élément de ressort (5, 9) destiné à incliner l'élément mobile (6) dans une position neutre;

une unité d'électroaimant (10, 11) tournée contre l'élément mobile (6); et

un appareil de commande (21) destiné à commander un courant (i) fourni à l'unité d'électroaimant (10, 11) afin d'entraîner l'élément mobile (6) de façon à réguler un déplacement d'un corps de soupape (3) associé à l'élément mobile (6), et le procédé comprenant:

l'exécution d'une commande d'initialisation de telle sorte que le courant (i) soit fourni en continu à l'unité d'électroaimant (10, 11) afin de déplacer l'élément mobile (6) placé dans la position neutre vers une position initiale;

la répétition de l'exécution des commandes de fourniture de courant en continu avec une interruption de la fourniture de courant en continu entre chacune d'entre elles;

le fait d'amener l'élément mobile (6) dans la position initiale uniquement par la dernière des commandes de fourniture de courant en continu; et

la détection d'une position (z) de l'élément mobile (6) par rapport à l'unité d'électroaimant (10, 11), caractérisé par

la réalisation d'un asservissement du courant (i) fourni à l'unité d'électroaimant (10, 11) pendant l'exécution de la commande d'initialisation par un gain d'asservissement (G1) sur la base de la position détectée (z) de l'élément mobile (6);

la variation du gain d'asservissement (G1) de telle sorte que, lorsque l'élément mobile (6) se rapproche de la position initiale, une vitesse (v) de l'élément mobile (6) arrivant dans la position initiale soit réduite lors de l'exécution de la commande d'initialisation de manière répétée jusqu'à ce la commande d'initialisation ait réussi à déplacer l'élément mobile (6) dans la position initiale pendant un démarrage du moteur.

Drawing